<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="js/react.development.js"></script>
    <script src="js/react-dom.development.js"></script>
    <script src="js/babel.js"></script>
</head>
<body>
    <div id="root"></div>
<script type="text/babel">
let isShow = true;
/*
    || 前边不成立，返回后边
    && 前边成立，返回后边
*/
// function isShow(){
//     if(){
//         return 
//     } else {
//         return
//     }
// }
ReactDOM.render(
    <div>
        {isShow&&<h1>React</h1>}
        <p>开课吧 React 课</p>
    </div>, 
    document.querySelector("#root")
);
</script>      
</body>
</html>